Lightweight structural panels are commonly formed of a sandwich of two flat resin facings and an intermediate core structure which are bonded together for use as flooring, bulk heads, and the like in commercial aircraft. Sandwich panels possess a desirous characteristic of being lightweight, while still providing relative high strength and stiffness needed for structural support in the aircraft.
Various forms of fasteners have been developed to be secured in a hole that has been cut into the aircraft panel, such as the sandwich panel fastener of U.S. Pat. Nos. 3,510,916, 4,846,612 and 5,536,344. Sandwich panels can utilize an exterior sheet or skin such as a glass fiber reinforced polyetherimide, which is then adhered by an adhesive to a core structure. The core structure can be a plurality of strips of metal foil or other thin lightweight structural material, which have been bent to form a plurality of honeycomb cells. The opposite side of the core structure is adhered to a similar resin sheet to form a sandwich configuration.
The fastener insert can be installed in a lightweight sandwich panel by first drilling a hole of the desired size for the particular insert. The insert is then inserted within the hole and is usually secured by a potting compound that will harden to anchor the insert. Various different methods have been used in an attempt to position the insert into the hole and to hold it in the proper position while permitting the potting compound to be introduced into the core structure and to set and hold the fastener in its properly aligned position.
It is desirable to provide an improved method of installing a fastener member into a sandwich panel in a manner in which manufacturing efficiency is improved while manufacturing costs are reduced.